| abstract |
The invention concerns the use in a cosmetic composition of at least a poly-aminoacid of general formula (1) in which X is —O—, —S— or —NR 3 ; R 1 represents in particular a hydrogen atom or a C 1 -C 40 alkyl radical; R 2 represents in particular a hydrogen atom or an optionally substituted alkyl radical; R 3 represents a hydrogen atom or an alkyl radical; R 4 represents a hydrogen atom or a radical such as NH 2 , OH, SH, —CHOHCH 3 , —CONH 2 ; n is a number greater than 1 such that the poly-aminoacid derivative molecular weight ranges between 200 and 200000. The invention also concerns the use of said derivatives for keratinous fibre strengthening and care. |